Somtimes My Clutch Motor Runs Backwards And Sometimes Forwards. Why?

[dikman]

This has got me intrigued. I'm not convinced that the dotted lines indicate another switch box (or something) - if that were the case I would expect some sort of indication on the drawing. Also, every other cct. that I've seen that switches out the cap/start winding at the very least shows a contact in that part of the cct. whereas this doesn't.

So, I got my spare Consew motor and removed the back cover (where the leads go in). Four wires disappeared into the motor body, a cap was mounted at the back with two wires also heading inside. I looked through the cooling slots, no centrifugal switch. Inside the switch box the four wires were connected as pairs to the line side. I separated the wires and did some testing with a meter. It's wired the same as the earlier diagram, i.e. two wires to one coil (run) and two wires to the start coil via a cap. I started it, but couldn't hear any centrifugal switch, but to be sure I removed the flywheel at the front - no switch.

This one is wired as per the OP's diagram, with the start cct. permanently connected. Not ideal, imo, bit it works and it's obviously cheaper to make.

Lovetolearn, as has been said earlier, replace the cap with the same value. If the motor is running fine, with only the direction being an issue then that's all that's wrong. Without the cap it's simply freewheeling at the start and you have a 50:50 chance which direction it will choose to run.

[Ole South]

@DrmCa

Oil? Liquid? Polypropylene/polyethylene glycol?... is that better? Sorry, I misspoke from too quickly responding, I thought the concept of the wetting agent was more important to the OP. There is a liquid or wax of some form in almost every run/start cap depending on its age/manufacturer. I'm guessing this motor is from the late 60's or 70's so either might be the internal wetter.

[Art]

This has got me intrigued. I'm not convinced that the dotted lines indicate another switch box (or something) - if that were the case I would expect some sort of indication on the drawing. Also, every other cct. that I've seen that switches out the cap/start winding at the very least shows a contact in that part of the cct. whereas this doesn't.

So, I got my spare Consew motor and removed the back cover (where the leads go in). Four wires disappeared into the motor body, a cap was mounted at the back with two wires also heading inside. I looked through the cooling slots, no centrifugal switch. Inside the switch box the four wires were connected as pairs to the line side. I separated the wires and did some testing with a meter. It's wired the same as the earlier diagram, i.e. two wires to one coil (run) and two wires to the start coil via a cap. I started it, but couldn't hear any centrifugal switch, but to be sure I removed the flywheel at the front - no switch.

This one is wired as per the OP's diagram, with the start cct. permanently connected. Not ideal, imo, bit it works and it's obviously cheaper to make.

Lovetolearn, as has been said earlier, replace the cap with the same value. If the motor is running fine, with only the direction being an issue then that's all that's wrong. Without the cap it's simply freewheeling at the start and you have a 50:50 chance which direction it will choose to run.

Of course, the question occurs as to what the dashed lines represent. However, your analysis does bear out with their use of the run cap in the circuit as opposed to a start cap. The run cap having a 100% duty cycle as opposed to a lesser duty cycle for a start cap. Since this application seldom has any startup load and runs at optimum, there is little benefit to a start cap other than getting things spinning in the right direction. If you are going to leave the start circuit "on" all the time, it explains the use of the run cap; as much as this whole design concept can. Why are those damned dashed lines there?

Art

[dikman]

I agree about the dashed lines, Art. That is what's so confusing. Ordinarily, dashed lines like that on a cct., as you said earlier, would indicate that there is something else in cct. and/or that they go via some other equipt (or that it may be a temporary connection). In this particular case that's not happening, so I'm perplexed as to why they used them. I'm blowed if I can think of a (sensible) reason for them.